Question

我有一个非常简单的KeyEvent：

@Override
public void start(Stage stage) throws Exception {
    Group root = new Group();
    Scene scene = new Scene(root);
    Canvas canvas = new Canvas( 900, 700 );

    scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            switch (ke.getCode()) {
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;
                case ENTER:
                    //ke.consume();
                    break;
                default:
                    break;
            }
        }});

我想达到的目标：我开始运行该程序，如果我按向上，向下，向左，向右输出写回我UP，DOWN，LEFT，RIGHT（它没有问题）。但！如果按下输入，如果我按下向上，向下，向左，向右，输入或其他按键不要将输出向上，向下，向左，向右写回。

所以我想停止KeyEvent＆＃34;运行＆＃34;当我按下ENTER按钮。

Answer 1

你有几个机会，这两个是我的第一个想法。

1）将您的关键事件的监听器存储为您的班级成员，然后在ENTER上取消注册。

private EventHandler<KeyEvent> keyHandler;


@Override
public void start(Stage stage) {
    final Scene scene = new Scene(new Group());
    stage.setTitle("Table View Sample");
    stage.setWidth(450);
    stage.setHeight(500);

    keyHandler = new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            switch (ke.getCode()) {
                case ENTER:
                    scene.removeEventHandler(KeyEvent.KEY_PRESSED, keyHandler);
                    break;
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;


                default:
                    break;
            }
        }};

   scane.addEventHandler(KeyEvent.KEY_PRESSED, keyHandler);

2）在ENTER按下，将布尔值存储到成员，如果设置了此成员，则使用该事件。

private Boolean enterPressed = false;

@Override
public void start(Stage stage) {
    final Scene scene = new Scene(new Group());
    stage.setTitle("Table View Sample");
    stage.setWidth(450);
    stage.setHeight(500);

   scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            if(enterPressed){
                ke.consume();
                return;
            }

            switch (ke.getCode()) {
                case ENTER:
                    enterPressed = true;
                    break;
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;

                default:
                    break;
            }
        }});

两者都在工作，选择你喜欢的任何东西。

KeyEvent停止侦听JavaFX

1 个答案: